Osseointegration of biochemically modified implants in an osteoporosis rodent model

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Bernd Stadlinger - , University of Zurich (Author)
  • P. Korn - , Department of Oral and Maxillofacial Surgery (Author)
  • N. Tödtmann - , Department of Oral and Maxillofacial Surgery (Author)
  • U. Eckelt - , Department of Oral and Maxillofacial Surgery (Author)
  • U. Range - , Institute for Medical Informatics and Biometry (Author)
  • A. Bürki - , University of Bern (Author)
  • S. J. Ferguson - , ETH Zurich (Author)
  • I. Kramer - , Novartis AG (Author)
  • A. Kautz - , Innovent e.V. (Author)
  • M. Schnabelrauch - , Innovent e.V. (Author)
  • M. Kneissel - , Novartis AG (Author)
  • F. Schlottig - , Thommen Medical AG (Author)

Abstract

The present study examined the impact of implant surface modifications on osseointegration in an osteoporotic rodent model. Sandblasted, acid-etched titanium implants were either used directly (control) or were further modified by surface conditioning with NaOH or by coating with one of the following active agents: collagen/chondroitin sulphate, simvastatin, or zoledronic acid. Control and modified implants were inserted into the proximal tibia of aged ovariectomised (OVX) osteoporotic rats (n = 32/group). In addition, aged oestrogen competent animals received either control or NaOH conditioned implants. Animals were sacrificed 2 and 4 weeks post-implantation. The excised tibiae were utilised for biomechanical and morphometric readouts (n = 8/group/readout). Biomechanical testing revealed at both time points dramatically reduced osseointegration in the tibia of oestrogen deprived osteoporotic animals compared to intact controls irrespective of NaOH exposure. Consistently, histomorphometric and microCT analyses demonstrated diminished bone-implant contact (BIC), periimplant bone area (BA), bone volume/tissue volume (BV/ TV) and bone-mineral density (BMD) in OVX animals. Surface coating with collagen/chondroitin sulphate had no detectable impact on osseointegration. Interestingly, statin coating resulted in a transient increase in BIC 2 weeks post-implantation; which, however, did not correspond to improvement of biomechanical readouts. Local exposure to zoledronic acid increased BIC, BA, BV/TV and BMD at 4 weeks. Yet this translated only into a non-significant improvement of biomechanical properties. In conclusion, this study presents a rodent model mimicking severely osteoporotic bone. Contrary to the other bioactive agents, locally released zoledronic acid had a positive impact on osseointegration albeit to a lesser extent than reported in less challenging models.

Details

Original languageEnglish
Pages (from-to)326-340
Number of pages15
JournalEuropean Cells and Materials
Volume25
Publication statusPublished - 2012
Peer-reviewedYes

Keywords

ASJC Scopus subject areas

Keywords

  • Animal model, Biomechanics, Histomorphometry, Implant, Osseointegration, Osteoporosis, Surface coating